Photogrammetric analysis is used to determine the position and attitude of a store after separation from an aircraft. Store is defined as any item released or dropped by the aircraft and includes weapons, fuel tanks, and other carriage items. "Far-field" refers to the distance of the store from the aircraft, generally beyond but including the flow field affects of the aircraft, following separation from the aircraft. In this case store position will be tracked for up to 10 seconds after separation involving distances of up to a half mile or more from the aircraft.
Photogrammetry involves the use of aerial photographs to produce maps and charts. Generally, photogrammetry works on the principle of stereo pairs of cameras producing overlapping image scenes. The area of common overlap is known as the stereoscopic overlap.
Current methods of far-field ballistic determination requires the use of one of a limited number of government precision bombing ranges available. Scheduling is particularly difficult in view of the limited number of facilities. The test aircraft flies over the range while being tracked by several (usually three) ground-based range precision cameras to gather Time-Space-Position Information (TSPI). This information correlates the aircraft's position only. Additional ground-based TSPI cameras, often up to three or more, are also required to determine the position of the store throughout its trajectory after being separated from the aircraft. TSPI data are processed and analyzed post-flight to provide a time-correlated comparison of aircraft and store positioning.
This method of determining far-field ballistic characteristics is extremely expensive, typically costing on the order of $30,000.00 per hour in 1996 dollars. Moreover, this method is dependent on the operational availability of a multitude of complex and expensive components and operators, including multiple TSPI cameras, government precision bombing ranges and multiple personnel to perform the filming. Additionally, this current methodology can only provide test store position (not attitude) information. Further, since the prior methods utilize ground-based cameras, the system is susceptible to the vagaries of the weather, e.g., fog, rain, low cloud cover, etc.
These and other disadvantages of current far-field ballistic determination systems and methods are sought to be overcome by the invention embodied by the preferred embodiment.